The present invention relates to the unloading of bulk bags used as containers for dry or moist particulate materials. The present invention more particularly relates to the unloading of bulk bag containers fabricated from cloth like material, such as woven polyester material, which is usually sewn in a cubical configuration.
Bulk bags made of heavy cloth material have been known in the art for sometime. It has also been known to provide the bag with heavy corner straps which support the bag when it is hung in a tower like support frame. The opposite end of the bag typically has an outlet spout which is aligned with the discharge unit of a receptacle, for example a conveyer, hopper or the like, through which the material is intended to be discharged.
To discharge the bag, the bag is hung in the support frame and material flows via gravity through the spout to the discharge unit. It is a characteristic of some particulate materials contained in a bag to resist or stop flowing out of the spout when the material remaining in the bag reaches the material""s angle of repose or bridges over the spout. Since the bottom of the bag, where it is attached to the spout, is typically not at angle greater than the material""s angle of repose, not all of the material will be discharged through the spout by gravity.
To address such, U.S. Pat. No. 5,184,759, commonly assigned with the present invention, discloses an apparatus which attaches to the spout and elongates the bag as material flows from the bag. As a result, the bottom of the bag forms more of a funnel shape, with the walls at an angle greater than the material""s angle of repose, and the material flows more freely through the spout.
While the apparatus disclosed in U.S. Pat. No. 5,184,759 has proven successful at promoting freer flow from bulk bags, the manner in which the bag spout is attached to the moveable spout member has not always been the most desirable. With that devise, material may build up about the outside portion of the moveable spout. When the spout is released, the built-up material, particularly if it is a powdery material, may spill and contaminate the work environment.
U.S. Pat. No. 5,341,959 issued to Ellis discloses a means of connecting a bag spout to a moveable spout member with an internal securing configuration. However, this configuration is complex to manufacture and difficult to use. Due to the internal connection, an operator may have insufficient clearance to effectuate a proper connection inside the moveable spout member, particularly if the bag spout is short.
Accordingly, there is a need for a bulk bag unloading apparatus which includes a simpler, cleaner attachment arrangement.
The present invention relates to a bulk bag unloading station wherein a bulk bag is suspended above a discharge receptacle. An assembly is provided for securing a spout extending from the bag to a discharge tube. The assembly comprises a clamp ring which defines a channel configured to receive the free edge of the tube therein and define a bag spout securing area. An actuator assembly is moveable between a first position where the clamp ring is spaced from the free edge and a second position where it overlies the tube free edge. In a preferred embodiment of the invention, the discharge tube is moveably mounted such that it extends the bag spout as the bag empties.